Police caught two buddies illegally using water from a fire hydrant in order to make a really cool backyard ice rink. Tony Nelin and Timmy Ryan, each 20 and from the suburbs outside Chicago, thought it would be “productive” to have the ice rink over the frigid winter months in Tinley Park. One of the kid’s parents signed off on building the backyard rink for $350.

The innovative youngsters, along with a couple of other friends, began filling it with water from a garden hose last week. After close to four hours, they decided it was going be too expensive. The friends borrowed 250 feet of fire hose from a relative who works for the fire department to finish the rink framed with lumber. The homemade frozen pond even includes a penalty box, according to the Chicago Tribune.

The custodian at Tinley Park High School discovered the fire hose connected to a running fire hydrant on school property and called police. Officers used expert detective skills, following the hose through a wooded area and right to the 91′ by 43′ partially frozen backyard ice rink.

The Chicago Tribune reports they used an estimated 26,000 gallons. That’s a lot, but in the end the expected bill for the water will be close to $130 dollars. The good news is that they will be able to keep the backyard rink because it was built on private property, and therefore it doesn’t need a special building permit. The four friends plan to split the expected fine and water fee.